Excess phase jitter cancellation method for SC relaxation oscillators

A practical jitter cancellation method for relaxation SC oscillators is presented. Two versatile switched-capacitor (SC) oscillators using the proposed excess phase jitter suppression technique are described. The jitter and the dependence of the oscillation frequency on the saturation voltages of operational amplifiers (op-amp) or comparators are eliminated. Therefore, there is no oscillation frequency limitation, except the one determined by the Nyquist rate. Because the frequency of oscillation of the proposed SC oscillators depends on a capacitor ratio and a reference voltage, the oscillators have excellent stability and accuracy. Experimental results showed good agreement with theoretical ones.